Necropath by Eric Brown

This new book is listed as "a Bengal Station novel", presumably set in the same location as the author's 2004 novel of that name, which I haven't read.

Bengal Station is a vast spaceport built in a far-future Bay of Bengal, receiving traffic from the many human-occupied worlds and occasional visits from members of various intelligent alien races. Rather more than a spaceport, in fact; it has many levels and is home to a crowded city of 25 million people. The city is zoned, with the best areas close to the top and/or enjoying direct sea views; the lower levels become increasingly down-market. This concept of a vertically stratified city is remarkably common in SF, presumably because it emphasises the associated social stratification.

Jeff Vaughan is a telepath, his natural potential having been substantially boosted artificially. He is employed by the spaceport to vet incoming ships for illegal immigrants, but is tired of his job and his life, and takes drugs to dull his mind to the constant mental pressure from the packed hordes living in the city. Chandra is a one of the few people he can tolerate; a detective with the Bengal Station police. Sukara is a "working girl" from Cambodia, searching for her lost younger sister who was last heard of in Bengal Station. These three lives and several others become intertwined as Vaughan begins to investigate some anomalous shipments from the human colony on Verkerk's World, which his boss (himself protected from telepathic intrusion) will not allow him to scan.

This is a traditional hard-SF thriller featuring interstellar travel, exotic drugs, mysterious aliens and a powerful new religion taking hold on Earth. Vaughan struggles to find out what is going on, only to find that the greatest threat comes from his own past. An entertaining read, well worth the time.